Tray-stacking machine



Oct. 5,1926. 1,601,971

S. A. KNAPP, JR

PRAY STAGKING MACHINE Filed April 14, 1924- 3 sheets-sheet JIM/Brita!war/gays Oct. 5, 1926. 1,601,971

S. A. KNAPP, JR

TRAY STACKING MACHINE Filed April 14, 1924 3 Shets-Sheet 2 S. A. KNAPP,JR

TRAY STACKING MACHINE Filed April 14, 1924 3 Sheets-Sheet 5 jive/1150f Iwvw/Cb. J

g i [@tarqqys Patented Oct. 5, 1926. r

UNITED STATES PATENT OFFICE.

SEWELL A. KNAPP, JR., OF SAN FRANCISCO, CALIFORNIA.

T-BAY-STACKING MACHINE.

Application filed April 14, 1924. Serial No. 706,287.

This invention relates to a conveying through one of the conveyors asseen on the mechanism, and particularly pertains to a line 10 of Fig. 8.tray stacker. I I Fig. 11 is a fragmentary view of a modi- It is theprincipal object of the present fied form of carriage fingeras seen inperinvention to provide an apparatus which spective. 60 may be operatedto mechanically stack and Referrin more particularly to the drawunstacktrays of fruit, vegetables, cans and ings, 10 an 11 indicate twoparallel vertical the like, said stacking devices being so decolumnstructures rigidly held in spaced signed as to be portable, thusenlarging its parallel relation to each other by suitable 10 effectiveuse, and being further novel in the structural members as indicated at12 and 65 fact that it will stack and unstack from two 13. Theseparallel columns carry a pluralstacks of trays at all times acting uponthe ity of conveyor members 14. which are driven uppermost tray or traysin the stack. along a rectilinear course of travel in a ver- The presentinvention contemplates the tical plane. The conveying members are 15 useof a superstructure mounted upon casters more clearly shown in Figs. 8to 10 inclusive, -70 to permit it to be moved from place to place, inwhich it will be seen that a horizontally said superstructure carrying aplurality of extending angle bar 15 is connected with sets of trayengaging members so designed hanger arms 16 and 17. These three memas toremove the uppermost tray or plurality bers when assembled from atriangle at the of trays ina stack of trays and to deposit points ofwhich rollers 18, 19 and 20 are ro- 7 this tray on top of another stackof trays. tatably disposed. The rollers 18 are adapted The invention isillustrated by way of exto move between parallel track members 21 amplein the accompanying drawings inand 22. The track members 21- extendverwhich; tically and are connected at their upper and 2 Fig. 1 is aView irf front elevation showing lower ends by track continuations 23and 24. 80 the complete structure with which the presrespectively. Thetrack portions 22 extend ent invention is concerned. in spaced parallelrelation to the pair of Fig. 2 is a fragmentary view in front eletracks21 and operate in conjunction with vation showing one of the columnstructures the track members 21 to provide vertical of the invention.guides along which the flanged rollers 18 Fig. 3 is a fragmentary viewin sectional may move. elevation showing the roller guideways of Therollers 18 are mounted on shafts 25 one of the column structures.carried by links of a conveyor chain 26. Fig. 4 is a fragmentary view insection The conveyor chain pursues a rectilinear 35 and elevationshowing one of the caster course of travel around a pair of upper 90mountings of the structure. sprockets 27 and 28 and a air of lower Fig.5 is a view in elevation as' seen on sprockets 29 and 30 which determinethe the line 5-5 of Fig. 1 showing the strucpath of travel of the chainand hold it distural details of one of the columns'and the posed inspaced relation to the track memmanner in which the tray conveyors arebers 21, 22, 23 and 24. The chain 26 may 95 propelled and maintained inan operating be driven in either direction through a drivposition. mgchain 29 and a jack shaft 31. The. Fig. 6 is a viewin elevation showingone jack shaft carries a sprocket 31 around of the columns as viewed inthe direction of which the driving chain 29 is led. A

v arrows 6-6 indicated in Fig. 1. sprocket 32 is also fixed on thisshaft and 1 Fig. 7 is a view in horizontal section carriesa motor chain33 leading to a sprocket through the machine as seen on the line 77 34of a reduction gear. set 35. This gear setof Fig. 1 and more clearlyindicates by dotis shown in Fig. 6 as being driven by a belt ted linesthe relative positions of one of the 36 leading from a motor 37,associated with conveyors to a tra one column of the machine. The motoris 1 Fig. 8 is an enlarged view in elevation of the reversible type sothat the present inshowing one of the conveyor members. vention may beused to stack and unstack Fig. 9 is a view in vertical section throughtrays of material.

Fig. 8 as seen on the line 99 of Fig. 8. The carriage structuregenerally indi- Fig 19 i a i w in horizontal section cated at 1% in F 5a P which mounted rollers 18, 19 and 20, is maintained with its crossframe member 15 in a constant horizontal position during the movement ofthe carriage by the conveyor shaft 26. The is brought about b engagementof the rollers 19 and 20 wit a rectangular track 38 comprising verticalsections 39 and 40 and connecting horizontal sections 41 and 42. Thepoint of intersection of these various track members is formed in theshape of a curved track or rail with suflicient arc to permit therollers 19 and '20 to conform thereto as the carriage changes itsdirection of travel and without tipping the carriage.

Acting in conjunction with the track structure 38 is a centrallydisposed rectangular track structure 41 comprising vertical trackmembers 42 and 43 complementary to the vertical tracks 39 and 40respectively, and horizontally connecting track portions 44 and 45parallel to the track portions 41 and 42 respectively.

It will e evident from examination of Fig. 5 that as the carriage moveshorizontally along its lower horizontal path of trave both of therollers 19 and 20 will be travelling along the lower track member 41,and that if the carriage is movin in the direction of the arrow a in ig.5, it will change its direction of travel to a vertical movement as theshaft hanger 25 passes around the sprocket 29, and the carriage thenmoves upwardly in the direction of the arrow b. During this upwardmovement roller-19 will travel along the outer rail 40, roller 20 willtravel along the inner rail 43, and the upper guide roller 18 willtravel along and between the rails 21 and 22.

\Vhen the carriage reaches the limit of its upward vertical movement andthe hanger shaft 25 passes around the sprocket 27, the roller 18 willtravel along the track 23 while rollers 19 and 20 will pass along andbetween track 42 and the short track section 45. After the hanger shaft25 has passed around the sprocket 28 the carriage will move downwardlyas the pulley 18 passes between the tracks 21 and 22 and the rollers 19and 20 move along vertical track sections 42 and 39 respectively.

Iuide rails 46 and 47 are provided as part of the column structure toform guiding members for the trays 48 which are being handled by themachine.

Carried by each of the carriage structures 14 is a pair of fingers 50.These fingers are mounted for vertical swinging movement around a pin 51supported in a suitable bearlng 52 forming a part of a horizontallyswinging member 53. Th swinging member is pivotally mounted relative tothe carriage structure on a shaft 54.

It will be understood that there are two finger structures and twoshafts 54 shown more clearly in Fig. 8 as being disposed mat ishorizontally the opposite ends of the horizontal frame member 15, and breference to Fig. 10, it will be seen that t e fingers when swinginghorizontally swing inwardly toward each other and assume positionsparallel and beneath the frame member 15. This swinging action isbrought about by the movement of two links 55 and 56 which are connectedto a lever 57 having opposite extending portions swinging simultaneouslyaround a shaft 58. The shaft 58 is disposed equidistant between the ins54 and extends verti cally to roject t rough an upper bearing 59 as welias a lower bearing 60.

The shaft 58 with its operating lever 57 may be actuated b two methods.In one instance by a vertical y disposed tray cam 61 secured to theshaft near its upper and lower ends and adapted to normally stand so asto be en aged by the side of a stack of trays and 8 to ie swung to thedotted line position indicated in Figs. 9 and 10. In addition the lever57 may be rotated by a roller 62 which is carried by a bell crank 63pivotally mounted upon the horizontal frame member 15. 9 The lower endof this bell crank is connected by a link 64 with the chain 58 so thatwhen the roller 62 on the free end of the bell crank is swung upwardlyby engagement with a horizontal cam member 65, and while the 9 carriageis moving along this lower horizontal path of travel, the fingers willbe swung to t eir innermost positions.

A coil spring 66 is disposed around the shaft 58 and acts to normallyrotate the shaft 1 58 and swing the fingers 50 to their outermostpositions and the track cam 61 to a position where it will engage thestack of trays. The exact configuration of the track cam is more clearlyshown in Figs. 8 and 9 1 where it will be seen to have inclined upperand lower portions 67 and 68 with an intermediate bow portion adapted tobe wedged against the side of a stack of trays and to swing the cam outof the way of the trays 1 and to thus rotate the shaft 58. It will beevident that'variations in cam proportions will be required with traysof various heights and containing material which space them differentdistances apart, and that this 1 design may also be changed to insurethat a plurality of the top trays may be picked up if desired.

While the foregoing description has been confined to the construction ofone of the columns 10 or 11 and one carriage structure 14 forming a artthereof, it is to be understood that t e columns 10 and 11 aresubstantially in duplicate, and that they each are fitted with carriagesarranged in horizontally aligned spaced relation to each other so thatthe fingers 50 of the two carriages may assume positions beneath andengaging the opposite sides of a tray in a manner to lift the tray whilemaintaining it in 130 In operation of this invention, it may bedesirable to move the entire structure from place to place, and withthat idea in view, front wheels 70 are provided as shown in Figs. 1, 5,and 6. These wheels are mounted for swinging movement 'on fork shafts 71and may be swung by a lever 72. Caster wheels 73 are disposed at theopposite side of the machine so that the entire structure may be readilymoved and accurately guided and positioned. In Fig. 11 of the drawingsis shown a form of finger 50 used when only vertical swinging movementof the finger is required, as for example, in the machine only intendedto stack trays.

In operation of the present invention, the entire structure is assembledas indicated in Fig. 1 with the complementary carriage structuresdisposed in horizontal alignment as there shown. The carriages will bedriven and will be maintained in their horizontally aligned positions aspreviously described. Assuming that trays are being stacked at astationmarked A in Fig. 5 and unstacked at a station marked B in the samefigure, the operation of the carriage mechanism will be as follows;

The carriage will pass horizontally in the direction of the arrow '-a in5 until it reaches a position in alignment along opposite sides of thestack of trays. This position will be accurately determined by firststacking the trays so that their corners are properly seated in theangles of the complementary members 46. r-iWhenv the carriage moves to acentrally aligned position along opposite sides of the stack of trays,the

. direction of the carriage will be changed from horizontal to verticaland the carriage will then travel upwardly in the direction of the arrowb in Fig. 5.

. Prior to this upward swinging movement, the roller 62 as indicated inFig. 9 will have been engaged by the straight horizontal cam 65 to swingthe fingers 50 inwardly and so that'they will clear the opposite sidesof the trays. This will also act to swing the cam member 61 inwardly toclear the sides of the trays. The carriages will then move upwardly, andas the operating roller 62 moves away from the cam 65, the tray cam 61will engage the ends of the trays and will thus be maintained in itsinoperative position. This 'will continue until the cam is moving off ofthe uppermost tray when the lower inclined face68 will cause the 61 togradually swing inwardly and simultaneously permit the fingers 50 toswing outwardly under the impulse of the coil spring 66. Before thecarriages clear the uppermost tray the fingers 50 will be in positionbeneath the tray and will engage the same as the carriage continues itsupward travel. It will then be supported by fourfingers 50, two uponeach side of the tray. The tray will then continue along its uppercourse of travel, thereafter passing horizontally at the top of thecolumns and thus will be lowered alongside of the guide angles As thetray comes to rest on the stack of trays the fingers 50 will be free dueto the fact that the lower inclined face 68 of the cam member 61 willstrike the tray. as it continues downwardly, and will swing the fingerhorizontally so that it will clear the succeeding trays in the stack.The cam will of course, be in engagement with the ends of the trays inthe stack as it continues down to the bottom of the stack, at which timethe roller 62 will strike the rail 65, and will continue to hold thefingers in their clearing position while the carriages move horizontallyand'completely beneath the stack of trays, and until the carriages comeinto alignment for upward movement along the side of the stack fromwhich the trays are to be removed, at which time the cams 61 will engagethe ends of the stack of trays, and will hold the fingers outofengagement therewith until the lower faces 68 ot' the cams have clearedthe uppermosttray in the stack, at which time the fingers 61 will againswing horizontally beneath the uppermost tray in the stack from whichthe trays are being removed. This will permit the carriagesto move freefrom the trays.- Attention is particularly directed to the, fact thatdue to the peculiar rectilinear path of travel followed by thecarriages,the structure may be compactly designed and will insure that the traysmay be picked from and stacked at points near the round level, whichwould not be the case 1f large sprocket wheels where used at the top andbottom of the structure, as is common practice in conveyor design. Itwill, therefore, be evident that due to thedesign here shown, theover-all height of the machine is materially decreased, thus making thedevice especially adapted for portable use.

It will be evident that there mustbe a for mechanically stacking andunstacking trays without danger of spilling their contents and withgreat rapidity due to the accurate mechanical action of the mechanism.

While I have shown the preferred form of my invention as now known tome, I wish it understood that various changes may be made in itsconstruction without departing from the spirit of the invention asdefined in the appended claims.

Having thus described my invention, what I claim and desire to secure byLetters Patent is:

1. A tray stacking machine comprising complementary conveying means,carriages carried by said means on a rectilinear path of travel forengaging the opposite ends of a tray, and automatically operating meansfor causing the carriages to engage and lift trays from the to of astack of trays.

2. A tray stac ring machine comprising complementary conveying means,carriages carried thereby. means on said carriages for engaging thetrays of a stack of trays as the carriages move upwardly past saidstack, and automatic means carried by the carriages and actuated byengagement with the stack of trays whereby the tray engaging means ofthe carriages will move heneath the uppermost tray in the stack and liftit from the stack.

3. A tray stacking machine comprising complementary conveying means,carriages carried thereby, means on said carriages for engaging thetrays of a stack of trays as the carriages move upwardly past saidstack, automatic means carried by the carriages and actuated byengagement with the stack of trays whereby the tray engaging means ofthe carriages will move beneath the u permost tray in the stack and liftit from the stack, and means whereby the tray carried by the carriagemay be arranged in another stack of superposed trays while the trayengaging means automatically moves away from the trays in the secondstack to permit continuous movement of the carriage.

4;. A tray stacking machine comprising a pair of continuous conveyorsmoving in parallel vertical planes at the opposite ends of a stack oftrays. complementary carriages carried by said conveyors and fitted witha plurality of tray engaging fingers, means for continuously maintainingsaid fingers in horizontal alignment during the complete cycle ofmovement of the carriages, and means for permitting the fingers to swingupwardly from their horizontal positions when the carriages are movingdownwardly along the opposite sides of a stack of trays, and means forsimultaneously swinging the fingers horizontally when the fingers havereached a position where they will move beneath a tray t'obe lifted.

5. A tray stacking machine comprising r a pair of endless chains havingrectilinear movement in parallel vertical planes, carriage members hungfrom said chains and adapted to be carried therewith along saidrectilinear path of travel, a plurality of fingers mounted on saidcarriages and pivoted for vertical movement upwardly from a normallyhorizontal position, means on the carriages, and cooperating means inthe vertical operating planes of the c011- veyor chains for maintainingthe fingers in horizontally aligned positions, means permitting thefingers to swing inwardly and horizontally, and operating means adaptedto engage opposite sides of a stack of trays to swing said fingers totheir inoperative horizontal positions and to release said fingers asthe carriages reach the top of the stack and in a position to permit thefingers to swing beneath the uppermost tray of the stack and to lift thetray with the carriages.

6. A tray stacking machine comprising a pair of complementary conveyorseach carrying guide rollers spaced from each other in a horizontalplane, a guide roller thereabove and spaced substantially midway betweensaid horizontal rollers, endless conveyor chains moving simultaneouslyto carry said carriages along substantially rectilinear paths of travel,and supporting 95 rails substantially bridging the distance between thevertical lengths of said chain and to receive the upper rollers of saidcarriages whereby the weight of the carriages and their load will besupported in said rails while the carriages move horizontally from onevertical path of travel to the other.

7. A tray stacking machine comprising a pair of complementary conveyorseach carrying guide rollers spaced from each other 105 in a horizontalplane, a guide roller thereabove and spaced substantially midway betweensaid horizontal rollers, endless conveyor chains moving simultaneouslyto carry said carriages along substantially rectilin- 110 ear paths oftravel, and supporting rails substantially bridging the distance betweenthe vertical lengths of said chain and to receive the upper rollers ofsaid carriages, whereby the weight of the carriages and 1 their loadwill be supported in said rails while the carriages move horizontallyfrom one vertical path of travelto the other.

8. A tray stacking machine comprising a pair of endless conveyor chainsadapted to 120 move in parallel vertical planes and along rectilinearpaths of travel, carriages pivotally suspended from said chains, saidcarriages having a horizontally extending tray engaging portion at theends of which guide 1 rollers are carried, and a third guide rollercarried on the pivotal mounting of the conveyor chain, and a horizontaltrack-way along which the horizontally aligned rollers of the carriagepass while the carriage is moving from one tray station to another,vertical trackways along which the horizontal rollers pass as thecarriage is being moved in one vertical direction in the machine,vertical trackways along which the horizontally aligned rollers pass asthe car riage is moving in the opposite vertical direction, verticaltrackways between which the upper carriage roller passes while thecarriage is moving along its opposite vertical path of travel, and ahorizontal track- Way receiving said upper roller and supporting theweight of the carriage while the carriage is being transferred from onevertical path of travel to the other.

9. A tray stacking machine including a conveyor unit comprising avertically disposed frame structure, four sprockets arranged in pairsand the pairs equally spaced from each other, a continuous chain passingaround all of said sprockets, means for driving the same, a conveyingcarriage supported from the chain carried therewith, means formaintaining said carriage in horizontal alignment while following therectilinear path of travel of the chain, and means for supporting theweight of the carriage while.

in two parallel and vertical planes, sprocket chains one led aroundeach" set of sprockets in each parallel plane and pursuing asubstantially rectilinear path of travel around said sprockets, meansfor driving said sprockets, complementary carriages mounted on saidchains and designedto support a load between the planes of the chainsand to convey said load in the rectilinear path of travel of the chains,and means for supporting the Weight of the carriages and their loadwhile said carriages are moving horizontally in their rectilinear pathof travel.

SEWELL A. KNAPP, JR.

